Just scored an oneida 3hp unit which needs a 20 amp 220v circuit. Super excited to get it going but then found out bad news. In my current sub panel it had appeared that I had space for 3 circuits, which I was going to run one dedicated for DC and the other two for various tools throughout garage. I plan to only run one 20' or so run with two circuits on it for 220 and just have long chords for each tool. Don't have a large space just a normal 2car space. After inspecting more and getting into the panel, I only have one spot. My question is can run another sub-panel be ran off of the current sub. The main panel and current sub are side by side and I should have space to just add another. Anyone ever do something like this?